Horner Syndrome in Children: A Clinical Condition with Serious Underlying Disease.

Aim Horner syndrome corresponds to the clinical triad of miosis, ptosis, and facial anhidrosis. These symptoms are related to injury of the oculosympathetic chain. In children, Horner syndrome is classified as congenital or acquired. While the diagnosis is made through clinical examination, there is some debate regarding the use of imaging modalities and the extent of anatomical coverage required. Methods Here, we describe two cases of children with acute Horner syndrome. We then review the literature about the different etiology and discuss the interest of some investigations. Results Case 1: An 8-month-old girl without personal or familial history, has presented a right acquired Horner syndrome without additional signs. Frontal chest radiography and ultrasonography of the neck and the abdomen was first achieved and returned normal. The cerebral and cervical magnetic resonance imaging (MRI) with angiographic sequences performed in a second time was also normal. Finally, an enhanced thoracic computed tomography (CT)-scan demonstrated a mass at the right pulmonary apex. Case 2: A 9-year-old boy without personal or familial history has presented an acute headache with loss of consciousness during a basketball competition. Upon waking up, the child has right hemiplegia, aphasia, and left Horner syndrome. The cerebral CT scan realized in the first line was normal. The MRI with angiographic sequences demonstrated M1 left carotid dissection with homolateral white matter infarction. Conclusion Imaging studies seem critical in delineating the nature and extent of any underlying pathology along the oculosympathetic pathway in children presenting a Horner syndrome. In these patients, a history of trauma or surgery may reduce the need for extensive systemic evaluation. Without such anamnesis, a decision to proceed with further evaluation is made with consideration of the relative incidence of tumor, especially neuroblastoma, or other treatable lesions. In this condition, MRI is the more sensitive and recommended investigation.